Heat transfer rates in fixed bed catalytic reactors

119 leaves ill.Printing process for illustrations in original document: Ozalid proces

The thermal conductivities of some hydrocarbons

The Bates Calorimeter for measuring the heat conductivities of hydrocarbons was partially reconstructed so as to diminish the heat loss through the walls of the iron container. This was done by imbedding some nichrome wire heating elements in the insulating materials just outside iron wall. The current sent through this coil was so controlled as to reduce the heat loss from the liquid at this point. A series of measurements on several hydrocarbons gave the results below. Trans decahydronaphthalene k₃₅ = 0.001155 Cis k₃₅ = 0.001178 N decane k₃₅ = 0.000652 N dodecane k₃₅ = 0.000654 N tetradecane k₃₅ = 0.000650 N hexadecane k₃₅ = 0.000650Applied Science, Faculty ofChemical and Biological Engineering, Department ofGraduat

E-business challenges for intermodal freight - Some international comparisons

Separate Canadian and Australian government-sponsored studies, both reporting in mid-2001, have investigated expected impacts of rapid growth in e-business on transportation infrastructure and services. The different viewpoints of these two studies allow consideration of implications for freight transportation in general and intermodal freight in particular. The findings reported, relating to supply chain changes, special challenges for rail- and sea-freight carriers, and changes in requirements for freight warehousing and interchange, have international relevance, which leads to suggested policy responses. The importance of e-business in affecting freight transportation should not be underestimated. Transportation experts interviewed in the Australian study unanimously considered this the issue of most consequence for transportation over the next 5 to 10 years. Both studies point to freight transportation having significant potential to aid economic growth from e-business and conversely to a lack of appropriate infrastructure to accommodate that growth

Sources of variability in greenhouse gas and energy balances for biofuel production: a systematic review

Across the energy sector, alternatives to fossil fuels are being developed, in response to the dual drivers of climate change and energy security. For transport, biofuels have the greatest potential to replace fossil fuels in the short-to medium term. However, the ecological benefits of biofuels and the role that their deployment can play in mitigating climate change are being called into question. Life Cycle Assessment (LCA) is a widely used approach that enables the energy and greenhouse gas (GHG) balance of biofuel production to be calculated. Concerns have nevertheless been raised that published data show widely varying and sometimes contradictory results. This review describes a systematic review of GHG emissions and energy balance data from 44 LCA studies of first- and second-generation biofuels. The information collated was used to identify the dominant sources of GHG emissions and energy requirements in biofuel production and the key sources of variability in published LCA data. Our analysis revealed three distinct sources of variation: (1) 'real' variability in parameters e.g. cultivation; (2) 'methodological' variability due to the implementation of the LCA method; and (3) 'uncertainty' due to parameters rarely included and poorly quantified. There is global interest in developing a sustainability assessment protocol for biofuels. Confidence in the results of such an assessment can only be assured if these areas of uncertainty and variability are addressed. A more defined methodology is necessary in order to allow effective and accurate comparison of results. It is also essential that areas of uncertainty such as impacts on soil carbon stocks and fluxes are included in LCA assessments, and that further research is conducted to enable a robust calculation of impacts under different land-use change scenarios. Without the inclusion of these parameters, we cannot be certain that biofuels are really delivering GHG savings compared with fossil fuel